food particles dont enter the bloodstream
the circulatory system
The blood entering from the lungs has a high oxygen content and the blood entering from the body is high in carbon dioxide.
To oxygenate the blood
Because it cleans the blood
so they can purified the air the goes into the heart
The blood leaving the lungs is loaded with oxygen, while blood entering the lungs is about to get oxygen from the respiratory system.
The blood absorbs oxygen from the lungs - enabling it to be transported throughout the body.
Blood entering the left atrium is oxygenated blood coming from the lungs that is pumped throughout the rest of the body.
Blood entering the right atrium is deoxygenated and saturated with CO2. Blood that is entering the left atrium has passed through the lungs and is oxygenated. It returns to the left atrium via the pulmonary vein and is saturated with oxygen. - Med Student
The aorta (largest artery in the body) carries oxygenated blood from the heart to the body. From the aorta, the oxygenated blood will eventually travel through smaller and smaller arteries in your body, until eventually entering the capillaries to be delivered to the desired area.
if blood entering the heart gets mixed with blood leaving the heart the the blood leaving the heart will get poluted. the blood entering the heart is poluted when it enters the heart, the heart cleans it up; so when the blood leaves the heart it is clean so if it gets polluted the person may get sick and this leads to his/her death.
If urine wasn't filtered in the kidney, the particles in the urine would cause your genitals to explode.